1. Technical Field
The present invention relates to a run flat tire.
2. Related Art
There is a pneumatic tire called a run flat tire that can run in a certain extent of distance even in the state that air pressure in a tire has reduced and reached 0 kPa by tire failure such as puncture. It is known to reinforce a side wall part by providing a side reinforcing rubber part on an inner surface of the side wall part as a technique for enabling run flat running in the state that an inner pressure has reduced as above (see JP-A-2013-224054, JP-A-2007-331422 and US2013/0037193A1).
Furthermore, JP-A-2013-224054 discloses that a rubber sheet is arranged along a turn-up part of a carcass ply in order to improve run flat durability in a bead part of a run flat tire. US2013/0037193A1 discloses that a side filler having a given 100% tensile stress is embedded at an outer wall surface side of a side wall part.
In a run flat tire of such a side reinforcing type, high rigidity rubber is used in a side reinforcing rubber part in order to suppress deformation of a tire during run flat running. However, a temperature of a side reinforcing rubber part is increased during run flat running, and as a result, rigidity of the side reinforcing rubber part is decreased, resulting in decrease of run flat durability.